Window regulators, which are used for controlling the movement of a windowpane, such as a vertically moveable side window in the door of a motor vehicle, take a variety of forms including cable-drum regulators. Known designs for cable-drum regulators typically include a drive means, such as a hand crank or an electric motor, a mounting bracket securing the fixture to a wall of the door, a drum, a drum housing mounted to the mounting bracket, and at least one cable wrapped at least once around the drum.
Cables typically have a ball or puck of metal at each end to prevent fraying and to provide a ready means for attaching the cable to another structure. In the most common designs a pair of cables are used. One ball of each cable fits into corresponding receiving grooves in the drum. At the other end the other balls fit into receiving seats or grooves in a glider assembly.
The glider assembly is usually fixedly attached to the window by an attachment means and slidingly attached to a track or guide rail which defines the travel of the windowpane between its open and closed positions. The cable is guided along its length between the glider assembly and the motor by guide means, such as sliders or pulleys. The cable is often covered with a sheath or conduit over at least a portion of its travel path to protect it from dirt, oil, the elements and the like. Operation of the motor or hand crank causes the drum to rotate. This unwinds cable in one direction and winds cable in the other direction. As the cable moves, it pulls the glider assembly and in turn, the window. In this way the cables transfer the necessary forces from the drive means to the glider assembly to raise and lower the window.
In known designs the glider assembly typically includes a metal glider wing with a plastic fitting injection molded around the wing. The plastic fitting acts to provide a low friction surface for the glider assembly to slide over the guide rail, and to provide a reduced-noise receiving surface for the cable end balls. In addition, a lower durometer rubber-like bumper is typically attached either to the glider assembly or at the lower end of the guide rail. The bumper serves as a cushioning downstop, halting windowpane travel path with reduced shock loading on the system.
Attaching and securing the cable end balls to the glider assembly in these designs raise several problems. If the cable end balls are attached at a position laterally offset from the longitudinal centerline of the guide rail such that the cables are not aligned with travel path of the windowpane, then the glider assembly will be subjected to torque loading which will increase wear in the glider assembly. In addition, the cable end balls can be attached to the inboard side of the glider assembly, that is, the side facing the rail. However, installation of the cable end balls to the glider assembly in this manner is awkward. Typically the glider assembly must be slid on from one end of the guide rail and the end balls must be attached to the glider assembly prior to installation of the glider assembly over the guide rail. This results in increased assembly time, cost and complexity.
Further, the plastic fitting is typically injection molded onto the wing. The injection molding cavity is formed to receive a specifically sized glider wing. While this is acceptable for any one window, a window of a different size may require a larger glider wing, for example, for optimum location of the attachment means. Therefore known designs require use of a different glider assembly for each size window.
It is an object of the present invention to provide a cable-drum regulator of improved design which, especially in preferred embodiments, is easy to manufacture and assemble, and reduces complexity and cost. It is a further object of the present invention to provide a cable-drum regulator with a glider assembly of improved design that allows for windowpanes of varying sizes. Additional objects and features of the invention will become apparent from the following disclosure taken together with the detailed discussion of certain preferred embodiments.